Human late-receptor potential and its clinical use in dyschromatopsia

The off response of the P III component isolated by aspartate in the human eyecup in vitro showed an initial rapid decay followed by a slow decay. The rapid decay in the human ERG originates mainly in cones. The rapid decay was also observed in human subjects. The spectral sensitivity curve of the rapid decay was found to be shifted toward short wavelengths in all nine protanopes tested. In these cases of protanopia, anomalous cone functions were indicated.     

Synthesis, miscoding specificity, and thermodynamic stability of oligodeoxynucleotide containing 8-methyl-2'-deoxyguanosine

8-Methyl-2'-deoxyguanosine (8-MedG) was synthesized by reacting dG under the methyl radical generating system and incorporated into oligodeoxynucleotides using phosphoramidite techniques. The site-specifically modified oligodeoxynucleotide containing a single 8-MedG was then used as a template for primer extension reactions catalyzed by the 3' --> 5' exonuclease-free (exo-) Klenow fragment of Escherichia Coli DNA polymerase I and mammalian DNA polymerase alpha. Primer extension catalyzed by the exo- Klenow fragment readily passed the 8-MedG lesion in the template while that catalyzed by pol alpha was retarded opposite the lesion. The fully extended products formed during DNA synthesis were analyzed to quantify the miscoding specificities of 8-MedG. Both DNA polymerases incorporated primarily dCMP, the correct base opposite the lesion, along with small amounts of incorporation of dGMP and dAMP. In addition, two-base deletion was observed only when the exo- Klenow fragment was used. The thermodynamic stability of 8-MedG in the duplex was also studied. The duplex containing 8-MedG:dG was more thermally and thermodynamically stable than that of dG:dG. The duplex containing 8-MedG:dA was more thermodynamically stable than that of dG:dA. We conclude that 8-MedG is a miscoding lesion and capable of generating G --> C and G --> T transversions and deletion in cells.     

Failure characteristics of osteoporotic vertebral bodies monitored by acoustic emission

The third lumbar vertebrae of nine elderly subjects (average age, 81.4 +/- 6.7 years) graded osteoporotic and the second to fifth lumbar vertebrae of a 37-year-old man graded as normal were used to investigate microdamage accumulation during quasi-static compression loading with an acoustic emission detection system. Mechanical parameters (apparent elastic modulus, stress, and strain) and acoustic emission event count rates were measured simultaneously. The normalized mean value of any mechanical parameters of normal group was significantly high with respect to that of osteoporotic group. The normalized mean value of cumulative acoustic emission event counts to maximum stress of the normal vertebrae was substantially small with respect to that of the osteoporotic vertebrae (p < 0.0005, z-test). Postloading microradiographs displayed fracture lines adjacent to the end plates in six vertebrae of osteoporotic group. These results are consistent with the hypotheses that microdamages of osteoporotic vertebral bodies are generated and accumulate at lower strains than those of normal vertebrae at a specific site.     

Selected organochlorine pesticides in the atmosphere of major Indian cities: levels, regional versus local variations, and sources

India has extensive production and usage of organochlorine pesticides (OCPs) for agriculture and vector control. Despite this, few data are available on the levels and distribution of OCPs in the urban atmosphere of India. Passive and active air sampling was therefore conducted between Dec 2006 and March 2007 in 7 metropolitan cities: New Delhi, Kolkata, Mumbai, Chennai, Bangalore, Goa, and Agra. Concentrations (pg·m(-3)) were as follows: HCHs 890-17000 (mean: 5400 ± 4110); DDTs 250-6110 (1470 ± 1010); chlordanes 290-5260 (1530 ± 790); endosulfans 240-4650 (1040 ± 610); and hexachlorobenzene 120-2890 (790 ± 510). HCHs observed in India appear to be the highest reported across the globe. Chlordanes and endosulfans are lower than levels reported from southern China. Passive sampling enabled within- and between-city variations to be assessed. As expected, paired-sample t-test analysis revealed higher regional than local variation. Comparisons with the limited data available from studies conducted in 1989 suggest general declines of HCHs and DDTs for most regions. γ-HCH dominated the HCH signal, reflecting widespread use of Lindane in India, although the isomeric composition in Kolkata suggests potential technical HCH use. High o,p'-/p,p'-DDT ratios in northern India indicate recent DDT usage. High HCB levels in the industrial areas of New Delhi and Kolkata indicate ongoing sources. Correlation between trans- and cis-chlordane implies ongoing usage. Endosulfan sulfate generally dominated the endosulfan signal, but high values of α/β-endosulfan at Chennai, Mumbai and Goa suggest ongoing usage. Backward trajectories were computed using the NOAA HYSPLIT model to trace the air mass history. Result shows local/regional sources of OCPs within India.     

Carbon dioxide reforming of ethanol over Ni/Y2O3–ZrO2 catalysts

Supported nickel catalysts of composition Ni/Y₂O₃–ZrO₂ were synthesized in one step by the polymerization method and compared with a nickel catalyst prepared by wet impregnation. Stronger interactions were observed in the formed catalysts between NiO species and the oxygen vacancies of the Y₂O₃–ZrO₂ in the catalysts made by polymerization, and these were attributed to less agglomeration of the NiO during the synthesis of the catalysts in one step. The dry reforming of ethanol was catalyzed with a maximum CO₂ conversion of 61% on the 5NiYZ catalyst at 800 °C, representing a better response than for the catalyst of the same composition prepared by wet impregnation.     

Luminescence Characteristics of YAG Glass–Ceramic Phosphor for White LED

Luminescence characteristics of Ce:Y₃Al₅O₁₂ (YAG) glass-ceramic (GC) phosphor for a white LED were investigated. The GC phosphor was obtained by a heat treatment of a Ce-doped SiO₂-Al₂ O₃-Y₂O₃ mother glass between 1300degC and 1500degC for the prescribed time period. The quantum efficiency (QE) of Ce³⁺ fluorescence in the GC materials, the color coordinate, and the luminous flux of electroluminescence of LED composite were evaluated with a blue LED (465 nm) set in an integrating sphere. The QE increased with increasing ceramming temperature of the as-made glass. The color coordinates (x, y) of the composite were increased with increasing thickness of the GC mounted on a blue LED chip. The effect of Gd₂O₃ substitution on the optical properties of the GC materials was also investigated. The excitation and emission wavelengths shifted to longer side up to Gd/(Y + Gd) = 0.40 in molar composition. As a result, the color coordinate of the LED with GdYAG-GC of various thickness shifted to closer to the Planckian locus for the blackbody radiation. These results were explained by partial substitution of Gd³⁺ ions in the precipitated YAG microcrystals, leading to the increase of lattice constant of unit cell, which was confirmed by XRD.     

Toward tunable and bright deep‐red persistent luminescence of Cr3+ in garnets

Garnet structure (A₃B₂C₃O₁₂) with three different cation sites is a very flexible host material widely used for w‐LEDs, solid‐state lasers, scintillators, and so on. In this work, we have successfully developed six different Cr³⁺‐doped garnets: Y₃Ga_4.99Cr_0.01O₁₂ (YGG:Cr), Gd₃Ga_4.99Cr_0.01O₁₂ (GGG:Cr), Lu₃Ga_4.99Cr_0.01O₁₂ (LuGG:Cr), Y₃Sc_1.99Cr_0.01Ga₃O₁₂ (YSGG:Cr), Gd₃Sc_1.99Cr_0.01Ga₃O₁₂ (GSGG:Cr), and Lu₃Sc_1.99Cr_0.01Ga₃O₁₂ (LuSGG:Cr), which exhibit persistent luminescence (PersL) due to Cr³⁺ emission matching well with both the response curve of the Si detector and the wavelength region of the first biological window (NIR‐I, 650‐950 nm). The main emission band of Cr³⁺ in these garnets can be easily tunable from the sharp R‐line emission due to the ²E (²G)→⁴A₂ (⁴F) transition in the strong crystal field to the broad band emission due to the ⁴T₂ (⁴F)→⁴A₂ (⁴F) transition in the weak one when Lu³⁺ in the A site and Ga³⁺ in the B site are, respectively, replaced by larger cations, Y³⁺/Gd³⁺ and Sc³⁺. Furthermore, based on the knowledge of 4f energy levels of 15 lanthanide ions in the host‐referred binding energy (HRBE) diagram, we took the GSGG host as a typical example to discuss the feasibility of four trivalent lanthanides (Sm³⁺, Eu³⁺, Tm³⁺, Yb³⁺) as potential sensitizers for enhancing Cr³⁺ PersL.     

Effect of humidity on human comfort and productivity after step changes from warm and humid environment

Subjective experiments were conducted to evaluate the effects of humidity on human comfort and productivity under transient conditions from hot and humid environment to thermally neutral condition. Two climate chambers, “Chamber 1” and “Chamber 2”, adjoined each other were used for this study. Subjects were exposed to 30 °C/70%RH air in Chamber 1 for 15 min with 2.0 met of metabolic rate. Then they moved into Chamber 2, where 4 humidity conditions, 30, 40, 50 and 70%RH were examined. Air temperature was adjusted to keep SET* constant at 25.2 °C for all conditions. Subjects were exposed in Chamber 2 for 180 min performing 2 kinds of simulated office work.

Positive effects of low humidity on subjective pleasantness were found under transient condition at low humidity due to more evaporation from human body, while no significant difference in thermal sensation and humidity sensation among 4 relative humidity levels was obtained. Subjective performance was found to be at the same level under all conditions. However, subjects reported to be more tired at 70%RH after humidity step change.